Description

At the moment we have different ways to test stuff in our internal crates, and they are different from each other:

• the parser tests use the testing strategy inherited from rslint. It works but it requires to steps (files generation and snapshot update). There's no way to pass configuration/options to the code;
• the formatter tests use the insta snapshots. There's a way to pass options but it doesn't follow the configuration, we should use the rome.json configuration instead;
• the linter testing infra is the the most up to date one, and I believe that's the one we should follow: it uses the insta snapshots and it accepts a rome.json configuration;

The idea would be to create an internal crate where we could create generic testing utilities where:

• the utility read files from a folder (like in the analyzer)
• the consumer parses the files like they want, because we support different files (JS, JSON, etc.)
• the utility reads a *.options.json file inside that folder and tries to de-serialize it into a Configuration type;
• the consumer extracts the information from Configuration;
• the utility exposes an utility to write snapshots;
• the consumer can write snapshots like it wants;
• the utility writes the snapshot to disk;

Ideally, as a starting point, we can copy what we have inside the rome_js_analyze, make it generic and then change the code inside rome_js_analyze/tests and rome_json_analyze/tests.

Then we should move to:

1. rome_json_formatter
2. rome_js_formatter
3. rome_json_parser
4. rome_js_parser

I would mark this issue as "good first issue" but I would expect some knowledge of Rust to begin with.